java - Mechanisms of setText() in JTextArea? -

i try show text in jtextarea in runtime. when use loop of settext show text in order, show text of last loop here code:

private void jbutton1actionperformed(java.awt.event.actionevent evt) {  (int i=0;i<10;i++)      jtextarea1.settext("example "+i); }                                         

i want show "example 1", "example 2",..,"example 9". show 1 time "example 9"

anyone can explain me??

settext that, "sets text" of field value provide, removing previous content.

what want jtextarea#append

if you're using java 8, option might stringjoiner

stringjoiner joiner = new stringjoiner(", "); (int = 0; < 10; i++) {     joiner.add("quang " + i); } jtextarea1.settexy(joiner.tostring()); 

(assuming want replace text each time actionperformed method called, can still use append)

update based on assumptions around comments

i "assume" mean want each string displayed short period of time , replaced next string.

swing single threaded environment, blocks event dispatching thread, loops, prevent ui been updated. instead, need use swing timer schedule callback @ regular intervals , make change ui on each tick, example.

import java.awt.borderlayout; import java.awt.eventqueue; import java.awt.event.actionevent; import java.awt.event.actionlistener; import javax.swing.jbutton; import javax.swing.jframe; import javax.swing.jpanel; import javax.swing.jscrollpane; import javax.swing.jtextarea; import javax.swing.timer; import javax.swing.uimanager; import javax.swing.unsupportedlookandfeelexception;  public class test {      public static void main(string[] args) {         new test();     }      public test() {         eventqueue.invokelater(new runnable() {             @override             public void run() {                 try {                     uimanager.setlookandfeel(uimanager.getsystemlookandfeelclassname());                 } catch (classnotfoundexception | instantiationexception | illegalaccessexception | unsupportedlookandfeelexception ex) {                     ex.printstacktrace();                 }                  jframe frame = new jframe("testing");                 frame.setdefaultcloseoperation(jframe.exit_on_close);                 frame.add(new testpane());                 frame.pack();                 frame.setlocationrelativeto(null);                 frame.setvisible(true);             }         });     }      public class testpane extends jpanel {          private string[] messages = {             "example 1",             "example 2",             "example 3",             "example 4",             "example 5",             "example 6",             "example 7",             "example 8",             "example 9",         };          private jtextarea ta;         private int index;          private timer timer;          public testpane() {             setlayout(new borderlayout());             ta = new jtextarea(1, 20);             add(new jscrollpane(ta));              jbutton btn = new jbutton("start");             btn.addactionlistener(new actionlistener() {                 @override                 public void actionperformed(actionevent e) {                     if (timer.isrunning()) {                         timer.stop();                     }                     index = 0;                     timer.start();                 }             });             add(btn, borderlayout.south);              timer = new timer(500, new actionlistener() {                 @override                 public void actionperformed(actionevent e) {                     if (index < messages.length) {                         ta.settext(messages[index]);                     } else {                         timer.stop();                     }                     index++;                 }             });         }      }  } 

have @ concurrency in swing , how use swing timers more details